Myxoma virus encodes an alpha2,3-sialyltransferase that enhances virulence.

Abstract

A 4.7-kb region of DNA sequence contained at the right end of the myxoma virus EcoRI-G2 fragment located 24 kb from the right end of the 163-kb genome has been determined. This region of the myxoma virus genome encodes homologs of the vaccinia virus genes A51R, A52R, A55R, A56R, and B1R; the myxoma virus gene equivalents have been given the prefix M. The MA55 gene encodes a protein belonging to the kelch family of actin-binding proteins, while the MA56 gene encodes a member of the immunoglobulin superfamily related to a variety of cellular receptors and adhesion molecules. A novel myxoma virus early gene, MST3N, is a member of the eukaryotic sialyltransferase gene family located between genes MA51 and MA52. Detergent lysates prepared from myxoma virus-infected cell cultures contained a virally encoded sialyltransferase activity that catalyzed the transfer of sialic acid (Sia) from CMP-Sia to an asialofetuin glycoprotein acceptor. Analysis of the in vitro-sialylated glycoprotein acceptor by digestion with N-glycosidase F and by lectin binding suggested that the MST3N gene encodes an enzyme with Galbeta1,3(4)GlcNAc alpha2,3-sialyltransferase specificity for the N-linked oligosaccharide of glycoprotein. Lectin binding assays demonstrated that alpha2,3-sialyltransferase activity is expressed by several known leporipoxviruses that naturally infect Sylvilagus rabbits. The sialyltransferase is nonessential for myxoma virus replication in cell culture; however, disruption of the MST3N gene caused attenuation in vivo. The possible implications of the myxoma virus-expressed sialyltransferase in terms of the host's defenses against infection are discussed.

• Authors: R J Jackson, D F Hall, P J Kerr
• Journal: Journal of virology (J Virol) Vol. 73 Issue 3 Pg. 2376-84 (Mar 1999) ISSN: 0022-538X [Print] United States
• PMID: 9971821 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• RNA, Messenger
• Sialyltransferases
• beta-Galactoside alpha-2,3-Sialyltransferase

Topics

• Amino Acid Sequence
• Animals
• Base Sequence
• Cell Line
• Chlorocebus aethiops
• Leporipoxvirus (enzymology)
• Male
• Molecular Sequence Data
• Myxoma virus (enzymology, genetics, pathogenicity)
• Open Reading Frames
• RNA, Messenger (analysis)
• Rabbits
• Sialyltransferases (genetics, physiology)
• Virulence
• beta-Galactoside alpha-2,3-Sialyltransferase